Rapid adaptation to mechanical tillage in weeds

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14464
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 39040:Plant protection science-related
• Research Institution: The University of Tokyo
• Principal Investigator: Yuya Fukano 東京大学, 大学院農学生命科学研究科(農学部), 助教 (70713535)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 雑草防除 / 進化 / 都市

Outline of Final Research Achievements

We Focused on the difference in plant density (i.e., the number of competitors) in urban and agricultural environments. We produced urban and agricultural weed lineage, cultivated them under the same conditions, and compared their traits to examine the ongoing evolution in response to competitors. The results showed that plants from farmland populations had higher growth rates than plants from urban populations in high-competition treatments, and vice versa in low-competition treatments. Among populations, those with larger height/width ratios (farmland populations) were more tolerant of above-ground competition in high-competition treatments, but among individuals, those with larger ratios had lower growth rates in low-competition treatments. More plants from farmland populations, which had thicker stems (and larger height/width ratios), survived after experimental tillage than plants from urban habitats with thinner stems.

Free Research Field

生態学

Academic Significance and Societal Importance of the Research Achievements

一般的なイネ科雑草であるメヒシバ(図1)を対象に、都市と農地では植物の草姿が遺伝的に分化していることを発見しました。
都市と農地では植物間の競争の強さが異なり、この違いが草姿を急速に進化させる選択圧になりうることを示しました。植物において、競争者への形質進化を示した初めての事例です。
農地に適応した直立型個体は雑草防除(ロータリー耕)への耐性がありました。急速な進化を考慮することで雑草管理がより効果的になる可能性があります。